Position control system

Claim 2

Position control system according to claim 14, wherein said current supply device includes a pole reversal device whereby direction of rotation of said direct current motor can be altered by polarity reversal of said current pulses.

Claim 3

Position control system according to claim 1, wherein polarity of said current supply device is determined by a direction of rotation of said actuating element.

Claim 4

Position control system for controlling linear displacement of an object having a direct current motor and a gear to convert rotary movement into linear movement comprising: a current supply device for generating current pulses of a pulse frequency having an amplitude and a pulse duration; a pole reversal device; a rotatable actuating element coupled with an angular step transmitter and a rotational direction sensor, wherein said pulse frequency of said current supply device is determined by a direction detected by said angular step transmitter and a polarity of said pole reversal device is determined by said rotational direction sensor; and speed determining means for determining a speed of movement of said object as a function of said pulse frequency, such that said speed determining means causes a slow proportional increase of said speed when said pulse frequency is below a threshold value and said speed determining means cause a significantly greater increase of said speed when said pulse frequency is above said threshold.

Claim 5

Position control system for controlling linear displacement of an object having a direct current motor and a gear to convert rotary movement into linear movement comprising: a current supply device for generating current pulses of a pulse frequency having an amplitude and a pulse duration; a pole reversal device; a rotatable actuating element coupled with an angular step transmitter and a rotational direction sensor, wherein said pulse frequency of said current supply device is determined by a direction detected by said angular step transmitter and a polarity of said pole reversal device is determined by said rotational direction sensor; and speed determining means for determining a speed of movement of said object as a function of said pulse frequency, such that said speed determining means causes a slow proportional increase of said speed when said pulse frequency is below a threshold value and said speed determining means cause a significantly greater increase of said speed when said pulse frequency is above said threshold.

Claim 6

Position control system according to claim 14, wherein when said pulse repetition frequency exceeds a second value said current pulses are superposed on one another to form a constant direct current such that said mean speed of said reduction gear driving said position changes remains constant.

Claim 7

Position control system according to claim 14 wherein said current supply device generates square-wave current pulses and capacitors are provided to round said square-wave current pulses.

Claim 8

Position control system according to claim 14, wherein said current supply device generates current pulses with an amplitude which is far in excess of a current required to overcome static friction of said direct current motor and said reduction gear (2).

Claim 9

Position control system according to claim 14, further comprising means for adjusting amplitude and/or time duration of said current pulses of said current supply device.

Claim 10

Position control system according to claim 1, wherein a proportionality factor between said pulse repetition frequency of said current supply device and angular velocity of said actuating element (51) is adjustable.

Claim 11

Position control system according to claim 14, wherein said reduction gear and said position changer generate a linear movement such that an individual current pulse causes a movement step smaller than 1 μm and said speed for pulse repetition frequencies above said threshold exceeds a value of 1 mm/s.

Claim 12

Position control system according to claim 14, further comprising a position transmitter and a threshold value switch, for reproducible positioning to a specified position.

Claim 13

Position control system according to claim 11, wherein said position changer comprises one of a focusing drive or drive of the object stage in a microscope.

Claim 14

Position control system according to claim 12, wherein said focusing drive is an actuating drive in an autofocus control loop.

Claim 15

A position control system comprising: a direct current motor including means for generating a first braking action; a reduction gear driven by said direct current motor including means for generating a second braking action, said reduction gear driving a position changer causing a change in position of a controlled object; and a current supply device generating current pulses and supplying said current pulses to said direct current motor, said current supply device including means for adjusting a pulse repetition frequency; wherein said first braking action and said second braking action combine such that said position changer is braked to a standstill between successive current pulses when said pulse repetition frequency is below a first value such that a mean speed of said reduction gear driving said position changer is substantially proportional to said repetition pulse frequency times a small proportionality factor; and said position changer does not come to a standstill between successive current pulses when said pulse repetition frequency is above a threshold value such that said means speed of said reduction gear driving said position changer greatly increases with an increase in said repetition pulse frequency above said threshold.

Claim 16

A position control system comprising: a direct current motor including means for generating a first braking action; a reduction gear driven by said direct current motor including means for generating a second braking action, said reduction gear driving a position changer causing a change in position of a controlled object; and a current supply device generating current pulses and supplying said current pulses to said direct current motor, said current supply device including means for adjusting a pulse repetition frequency; wherein said first braking action and said second braking action combine such that said position changer is braked to a standstill between successive current pulses when said pulse repetition frequency is below a first value such that a mean speed of said reduction gear driving said position changer is substantially proportional to said repetition pulse frequency times a small proportionality factor; and said position changer does not come to a standstill between successive current pulses when said pulse repetition frequency is above a threshold value such that said means speed of said reduction gear driving said position changer greatly increases with an increase in said repetition pulse frequency above said threshold.